Electric call



(No Model.) 2 Sheets-Sheet 1,

,R. M. HUNTER. Electric Gall. No. 242,451. Patented June 7,188i.

N. PETERS, Photo-Lithographer, Wilmington. D. (I

(No Model.) 2 Sheets-Sheet 2.

R. M. HUNTER.

Electric Gall. No. 242,451. Patented June 7,1881.

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RUDOLPH M. HUNTER, OF PHILADELPHIA, PENNSYLVANlA.

ELECTRIC CALL.

SPECIFICATION forming part of Letters Patent No. 242,451, dated June '7, 1881,

Application filed January .27, 1881. (No model.)

To all whom it may concern:

Be it known that I, RUDOLPH M. HUNTER, of the city and county of Philadelphia, and State of Pennsylvania, have invented an Improvement in Electric Calls, of which the following is a specification.

My invention relates, broadly, to electrical signals, but more particularly to telephonic calls; and it consists in the construction and adaption of a balanced, or nearly balanced, lever, or its equivalent, to make one contact in a local circuit at each and ever station further, the combination, with such a lever, of mechanism operated by an electric current in connection with the line-current, whereby two contacts are made in the local circuit; further, in the arrangement of the line and signal currents; and, finally, in minor details of construction and arrangement, as more fully set forth in the following specification, and shown in the accompanying drawings, which form part thereof.

The object of my invention is to arrange an electric signal or call at every station, and have said electric signals or calls all connected to a single wire which is in communication with the ground at one end and the central-station signal and battery at the other, to enable the central-station officer to call any station on the line over a signal-wire, or allow any station to call any other station at will over the same wire, thereby obviating the necessity of separate wires from the central office to each and every station.

This invention has, further, for its object the adaption of long telephonic circuits in the country, city, or suburbs, dispensing entirely with the central station. Heretofore this has been done through the agency of increased currents and clock-work mechanism but this is objectionable, inasmuch as the former is expensive and troublesome, and the latter is complicated, uncertain, and liable to get out of order. This is very objectionable, since one station being out of order will necessitate a re-examination of every station and a setting of the instrument. In my apparatus I overcome all of these objectionable features, as hereinafter set forth.

In the drawings, Figure 1 is a side elevation of my improved electric signal or call apparatus. Fig. 2 is a perspective view of the gravity lever contact mechanism. Fig. 3 is an end elevation of same. Fig. 4 is a modified form of contact-circle, shown as sectioned on a" a: of Fig. 5. Fig. 5 is across-section of same on line y 3 Fig. 4. Figs. 6, 7, 8, and 10 show arrangements of the line and stations. Fig. 9 shows modified arrangement of local circuit.

A is the base-plate, and B the brass frame to support and carry the contact-wheel O and lever G. The contact-wheel O is made ofnonconducting material, and is secured to a shaft, E, carried in adjustingscrews E.

To the shaft E is secured a ratchet-wheel, D, which is rotated by a pawl, I, pivoted to lever G, and kept in contact with the ratchetwheel by a spring, 45. Any other device for rotating the contact-wheel U regularly may be used.

' The wheel 0 is equally divided aboutits circumference, which divisions correspond to the number of ratchet-teeth on wheel D. The axle E is connected by a conductor, F, with one division on the peripheryot'the contact-wheel 0; but each station has a different adjustment or contact.

The lever G is pivoted at H to support B, and its vibration is governed by the adjustingscrews 1) b.

Near the pivots H, and on the side opposite the pawl I, is the armature, and an extension, G, of the lever, and an arm, g, projecting upward therefrom. Said lever G is oscillated in one direction by a magnet, J, and in the other by a spring, J. The magnet J may be in direct connection with the line-wire, or may derive its magnetism from a local current generated in the local battery and governed by the relay U, which is in direct connection with the main line V, which is provided with a make or break key, N, as the case may be.

Secured to frame or base A. is a standard, K,

which carries a nearly-balanced lever, L, which is pivoted at M. One end of thislever may be screw-threaded and provided with an adjusting-weight, L, and the other with adjusting contact-point N.

Secured to the base A, and in contact with the periphery of the contact-wheel O,isasprin g, Q, the secured end of which is connected to a wire, It, in communication with the pivots M and lever L. Secured to the under part of the lever L, or upon the arm g, is a non-conductin g or insulator plate.

Secured to the base A through the pillar O is the anvil O, which is insulated and is located under the contact-point N. This anvil O is connected to the circuit-wire S at one end, the other end being connected to the shaft E of the contact-cireleO, and provided with thecallbell T and local battery T.

To the pillar O is secured a standard or guide, 0, to which is pivoted, at p, a lever, P, which is pressed toward lever L by a delicate spring, F, and is provided at the bottom with a foot, 1), against which the lever-extension G strikes in its downward movement. To retard the descent of the contact-point N by the oscillation ot the lever L, I prefer to wrap the lever with a narrow band of chamois-skin, L", which rubs against the guide 0.

If desired, instead of rotating the contactwheel 0 it may be fixed, as at C, and the tinger F rotated and the contacts Q, set rigid to suit each station, the contact being made by the end of finger F resting upon the conductor Q. The linger F is pressed against the contact-circle by a spring, 0.

The arrangement of line-wire is shown in Fig. 6, when the central station is to be used.

The operation is as follows: The number of the station corresponds to the number on the contact-wheel (J at which the conductor F is set. It central wishes to call station 3, he presses upon his key three short strokes and then holds the key down. This causes the contact-wheel to be rotated until the conductor F is in contact with spring Q at station 3, and allows the contact-point N to fall upon anvil O and complete the local circuit. The completed local circuit takes place only at station 3, for at all other stations one contactthe one on thecontaet-wheel-is wantin Hence station 3 alone is called. If central desires to call station 10, he presses ten short strokes upon his key and then holds it down. The contact is made between conductor F and spring Q, and the contact is made through the contactpoint N and anvil, and the local circuit S E F Q R L N 01's completed and the bell responds.

The lever L when up is supported by levercatch P, and when the extension G of lever Gr descends it strikes the footp, throws back the top of the catch-lever, and allows the lever L to oscillate and the contact point N to descend but if a short stroke of the key is made, the extension G and arm 1 is ascending before the contact between N and O is made, and the arm g strikes the insulator Z and throws the lever L up again, and the catch-lever locks it there.

If a long stroke of the key is made, the leverextension G and arm y do not ascend before the contact between N and O is made, and consequently this contact is completed, and as the contact on the contact-wheel is always made first, the bell will ring when the two contacts are made, and then only. The contact on the wheel 0 governs the station to ring, and the lever-contact makes the rin If the wheelcontact alone were used, a single rotation of said wheel would ring up every station on the line; hence two contacts must be used, and as every instrument in each station works in exactly the same manner a mistake cannot be made.

If the central station alone is to do all of the calling, the other stations do not require keys, and the current will only be used when operating the instruments, and by a contact-key; but when each and every station is to operate the call at will, then the current must be con tinuous and break-keys used. In this last case one or more spaces on the contaet-circle must be reserved for resting-points, or points in which two contacts can never be made on any instrument in the line.

The disk or contact wheel may be operated by clock-work or synchronous movement but I make no claim to such constructions, as they are in common use.

The line shown in Fig. 7 is designed to represent a continuous current without acentral ofiice.

The lines shown in Fig. 8 are arranged separatcly for the telephones and calls. The calls in this case are operated by a derived current over wire V, orone developed out of the main current over V, upon which the telephones are located. By this arrangement one station may call another station on wire V and then open his key. It will then be impossible for any one to interrupt him by signaling until finished talking over wire V, and when he closes the key.

The advantage of this arrangcmentot' wires is evident when we consider carefully its method of working. Supposing the main wire and derived wire to be of the same diameter, then the resistance of the telephonic wire will equal that of the signal-wire, and when both circuits are closed the principal current, or that which passes over both wires, will be stronger than the primitive current, or thatin the wire before the derived currentbranches off. Now, when it is desired to signal the operator will open the telephonic or main circuit and signal over thederived wire. This will increase the power of the current in the signal-wire and operate the signals more effectively. After signaling the operator closes the telephonic circuit and opens the derived or signal circuit, thereby increasing the power of the current on the telephonic circuit, and at the same time preventing interruption, as set forth above. This use of the derived current in telephony has particular advantages in the country suburbs, and even in the city. By simply making the signal-wire larger than the line-wire, or vice versa, we can proportion the power of the current to work the signals or the telephones.

Fig. 10 shows an arrangement in which the currents from both ends are balanced, and no electricity used unless the instruments are bein g worked, in which case they are grounded at the operating-station.

Fig. 9 shows a modified arrangement of Fig. 1, in which the local-circuit wire S is a contact with the periphery of the contact-wheel, and

IIC

ject-matter of another application.

the center of the latter is in connection with the balanced lever L.

The single wire may be used as the telephonic circuit as well as the signal-circuit, and when thus used the signal apparatus will not be operated by the undulatory currents developed in the telephone-trailsmitter.

Although this invention is particularly adapted to telephonic purposes, it can nevertheless be used for telegraphy and many other purposes.

I do not confine myself to the construction of apparatus shown, or to the nearly-balanced lever, for a pendulum would operate in precisely the same manner, it properly arranged, and is clearly within the scope of my invention,for my invention comprchends, broadly, a lever suspended in the air and operated through the agency of the line-current to fall and complete an open local circuit. By allowing the contact-point of the lever to fallupon the contact-piece 011 the contact-wheel one contact alone will be necessar Y to complete the local circuit; but this construction will form sub- Having now described my invention, what Iclaim as new, and desire to secure by Letters Patent, is

1. An electric-signal apparatus consisting of a disk or wheel having one contact-point, in combination with a nearly-balanced lever having another contact, and suspended in the air and free of the disk, connectingdevices, and the main-line circuit, said mechanism operating to make two contacts in a local circuit, one being made positively by the line-current or an induced current and the other by gravity, substantially as and for the purpose specified.

2. In an electric signal, the combination of a wheel having one contact-point and connecting mechanism, and operated by an electromagnet, and a nearly-balanced lever, or its equiva lent, having another contact-point, said lever completing the local circuit, which passes through the contact-wheel at one point in its circumference, substantially as and for the purpose specified.

3. In a signal apparatus, a nearly-balanced lever, or its equivalent, suspended in an unbalanced position, and operating by gravity to make a contact in a local circuit, said lever bein g controlled through the agency of the arm ature-leve'r and intermediate mechanism, sub stantially as and for the purpose specified.

4. In an electric signal, a contact-wheel, 0, having a single contact and operated by an electro-magnet, in combination with an arm, g, attached to the magnet-armature, and a nearly-balanced lever, L, or its equivalent, substantially as and for the purpose specified.

5. In an electric signal, the combination of contact-wheel O, shaft E,spring Q, mechanism to rotate the wheel 0, magnet J, lever Gr, provided with extension G and arm g, lever L, pivoted at M, latching mechanism to release lever Ii, contact-pointN, anvil 0, wire It, spring J, local circuit S, bell-call T, and battery '1, substantially as and for the purpose specified.

6. In an electric call or signal, the lever L, pivoted at M, adjustable weight L, contactpoint N, and friction-pad L, with guide 0, and anvil O, substantially as and for the purpose specified.

7. A telephonic-signal circuit derived from the main line or telephonic circuit, said circuits being provided with a series of stations, said stations being respectively provided with a telephonic transmitter and a receiver, in connection with the main line, and an electricsignal and a switch or key to break a circuit connected with the derived or signal circuit, substantially as and for the purpose specified.

S. A single line-wire, in combination with a series of stations located thereon, and battery, each station being provided with a telephonic trausmitter and receiver, a local circuit, and a signal apparatus provided with two contacts to control said local circuit, substantially as shown and described.

9. In an electric signal, acontact-wheel provided with a contact-plate upon one point in its circumference, in combination with a nearly-balanced lever suspended in the air and free of the wheel, and intervening devices, said lever beingprovided with a contact-point, and being in the same local circuit as the contact-piece on the contact-wheel, substantially as and for the purpose specified.

10. In an electric signal, a nearly-balanced lever pivoted at or near the middle and oscillated by gravity in one direction, and by the armature-lever of the electro-magnet, or an extension thereon,in the other direction, to control a local circuit, said lever being separate and distinct from the armature-lever, substantially as and for the purpose specified.

11. In an electric signal, a nearly-balanced lever oscillated by gravity and the armaturelever of an electro-magnet, or by an extension on said lever, in combination with a trip operated by an extension of said armature-lever, to control the oscillation of said nearly-bah anced lever in one direction, and when makingcontact, or tending to make contact, to close the local circuit, substantially as and for the purpose specified.

12. In a system of telephony, a main circuit and its battery, said main circuit being provided at every station with a telephonic transmitter and receiver and means to break the circuit, in combination with a derived or signal circuit derived from the main circuit, said derived circuit being provided with signal apparatus and keys to break the circuit, to correspond to the telephones, as and for the purpose specified.

In testimony of which invention I hereunto set my hand.

Witnesses:

LOUIS J. MAros, W. WILLIAMS.

RUDOLPH M. HUNTER,

IIS 

